diff --git a/CHANGES/5515.misc b/CHANGES/5515.misc
new file mode 100644
index 00000000000..e3d810b17f6
--- /dev/null
+++ b/CHANGES/5515.misc
@@ -0,0 +1 @@
+Deprecate ``@unittest_run_loop``. This behaviour is now the default.
diff --git a/aiohttp/test_utils.py b/aiohttp/test_utils.py
index 20abe2c8088..4cb70c8cb22 100644
--- a/aiohttp/test_utils.py
+++ b/aiohttp/test_utils.py
@@ -2,12 +2,12 @@
 
 import asyncio
 import contextlib
-import functools
 import gc
 import inspect
 import os
 import socket
 import sys
+import warnings
 from abc import ABC, abstractmethod
 from types import TracebackType
 from typing import (
@@ -472,17 +472,16 @@ async def get_client(self, server: TestServer) -> TestClient:
 
 def unittest_run_loop(func: Any, *args: Any, **kwargs: Any) -> Any:
     """A decorator dedicated to use with asynchronous methods of an
-    AioHTTPTestCase.
+    AioHTTPTestCase in aiohttp <3.8.
 
-    Handles executing an asynchronous function, using
-    the self.loop of the AioHTTPTestCase.
+    In 3.8+, this does nothing.
     """
-
-    @functools.wraps(func, *args, **kwargs)
-    def new_func(self: Any, *inner_args: Any, **inner_kwargs: Any) -> Any:
-        return self.loop.run_until_complete(func(self, *inner_args, **inner_kwargs))
-
-    return new_func
+    warnings.warn(
+        "Decorator `@unittest_run_loop` is no longer needed in aiohttp 3.8+",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    return func
 
 
 _LOOP_FACTORY = Callable[[], asyncio.AbstractEventLoop]
diff --git a/docs/testing.rst b/docs/testing.rst
index d722f3aef39..1cf316a3965 100644
--- a/docs/testing.rst
+++ b/docs/testing.rst
@@ -243,7 +243,7 @@ Unittest
 To test applications with the standard library's unittest or unittest-based
 functionality, the AioHTTPTestCase is provided::
 
-    from aiohttp.test_utils import AioHTTPTestCase, unittest_run_loop
+    from aiohttp.test_utils import AioHTTPTestCase
     from aiohttp import web
 
     class MyAppTestCase(AioHTTPTestCase):
@@ -259,26 +259,11 @@ functionality, the AioHTTPTestCase is provided::
             app.router.add_get('/', hello)
             return app
 
-        # the unittest_run_loop decorator can be used in tandem with
-        # the AioHTTPTestCase to simplify running
-        # tests that are asynchronous
-        @unittest_run_loop
         async def test_example(self):
-            resp = await self.client.request("GET", "/")
-            assert resp.status == 200
-            text = await resp.text()
-            assert "Hello, world" in text
-
-        # a vanilla example
-        def test_example_vanilla(self):
-            async def test_get_route():
-                url = "/"
-                resp = await self.client.request("GET", url)
-                assert resp.status == 200
+            async with self.client.request("GET", "/") as resp:
+                self.assertEqual(resp.status, 200)
                 text = await resp.text()
-                assert "Hello, world" in text
-
-            self.loop.run_until_complete(test_get_route())
+            self.assertIn("Hello, world", text)
 
 .. class:: AioHTTPTestCase
 
@@ -361,16 +346,13 @@ functionality, the AioHTTPTestCase is provided::
    .. note::
 
       The ``TestClient``'s methods are asynchronous: you have to
-      execute function on the test client using asynchronous methods.
-
-      A basic test class wraps every test method by
-      :func:`unittest_run_loop` decorator::
+      execute functions on the test client using asynchronous methods.::
 
          class TestA(AioHTTPTestCase):
 
-             @unittest_run_loop
              async def test_f(self):
-                 resp = await self.client.get('/')
+                 async with self.client.get('/') as resp:
+                     body = await resp.text()
 
 
 .. decorator:: unittest_run_loop:
@@ -381,6 +363,10 @@ functionality, the AioHTTPTestCase is provided::
    Handles executing an asynchronous function, using
    the :attr:`AioHTTPTestCase.loop` of the :class:`AioHTTPTestCase`.
 
+   .. deprecated:: 3.8
+       In 3.8+ :class:`AioHTTPTestCase` inherits from :class:`unittest.IsolatedAsyncioTestCase`
+       making this decorator unneeded. It is now a no-op.
+
 
 Faking request object
 ---------------------
diff --git a/tests/test_loop.py b/tests/test_loop.py
index 24c979ebd55..914b8f1fc4d 100644
--- a/tests/test_loop.py
+++ b/tests/test_loop.py
@@ -5,7 +5,7 @@
 import pytest
 
 from aiohttp import web
-from aiohttp.test_utils import AioHTTPTestCase, unittest_run_loop
+from aiohttp.test_utils import AioHTTPTestCase
 
 
 @pytest.mark.skipif(
@@ -31,7 +31,6 @@ async def get_application(self):
     async def on_startup_hook(self, app):
         self.on_startup_called = True
 
-    @unittest_run_loop
     async def test_on_startup_hook(self) -> None:
         self.assertTrue(self.on_startup_called)
 
diff --git a/tests/test_test_utils.py b/tests/test_test_utils.py
index c268e71073f..d393834927f 100644
--- a/tests/test_test_utils.py
+++ b/tests/test_test_utils.py
@@ -102,7 +102,6 @@ class TestAioHTTPTestCase(AioHTTPTestCase):
     def get_app(self):
         return _create_example_app()
 
-    @unittest_run_loop
     async def test_example_with_loop(self) -> None:
         request = await self.client.request("GET", "/")
         assert request.status == 200
@@ -134,6 +133,17 @@ async def test_get_route() -> None:
         await test_get_route()
 
 
+def test_unittest_run_loop() -> None:
+    with pytest.warns(
+        DeprecationWarning,
+        match=r"Decorator `@unittest_run_loop` is no longer needed in aiohttp 3\.8\+",
+    ):
+
+        @unittest_run_loop
+        def foo():
+            pass
+
+
 def test_get_route(loop, test_client) -> None:
     async def test_get_route() -> None:
         resp = await test_client.request("GET", "/")